The present invention relates to an ultra sonic method and apparatus for automatically controlling the opening and closing of moving doors, particularly sliding doors.
Automatic door control systems are gaining wide-spread use in order to control traffic into or out of enclosed spaces which are heated or cooled by airconditioning systems. Such door control systems not only must detect and respond to objects moving towards the closed doors, but must also provide protection against injury by a closing or opening door, and further, should minimize the time the door is in the open condition in order to minimize wastage of the energy used for airconditioning the enclosed space.